U.S. patent application number 13/660638 was filed with the patent office on 2013-05-02 for control contact driving system.
This patent application is currently assigned to ABB TECHNOLOGY AG. The applicant listed for this patent is ABB TECHNOLOGY AG. Invention is credited to Raffael Schnell, Nedyalko SLAVOV.
Application Number | 20130106469 13/660638 |
Document ID | / |
Family ID | 45747063 |
Filed Date | 2013-05-02 |
United States Patent
Application |
20130106469 |
Kind Code |
A1 |
SLAVOV; Nedyalko ; et
al. |
May 2, 2013 |
CONTROL CONTACT DRIVING SYSTEM
Abstract
A control contact driving system for a plurality of power
semiconductor devices includes a driver unit providing reference
currents for pulling-up and/or pushing-down control contacts of the
semiconductor devices, and a distributor unit amplifying and/or
distributing the reference currents to the control contacts. The
current distributor unit includes a pull-up current mirror having a
plurality of PMOS based transistors, and a push-down current mirror
having a plurality of NMOS based transistors. First main contacts
of all pull-up transistors are connected in parallel to a first
voltage source, and first main contacts of all push-down
transistors are connected in parallel to a second voltage source.
Second main contacts of a respective one of the pull-up transistors
and push-down transistors are connected together for providing
current to a respective control contact. The control contacts of
the pull-up transistors and the push-down transistors are all
connected in parallel to the current driver unit.
Inventors: |
SLAVOV; Nedyalko; (Zurich,
CH) ; Schnell; Raffael; (Seon, CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ABB TECHNOLOGY AG; |
Zurich |
|
CH |
|
|
Assignee: |
ABB TECHNOLOGY AG
Zurich
CH
|
Family ID: |
45747063 |
Appl. No.: |
13/660638 |
Filed: |
October 25, 2012 |
Current U.S.
Class: |
327/109 |
Current CPC
Class: |
H03K 17/18 20130101;
H03K 17/127 20130101; H03K 17/0412 20130101; H03K 17/063 20130101;
H03K 17/163 20130101 |
Class at
Publication: |
327/109 |
International
Class: |
H03K 17/06 20060101
H03K017/06 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 26, 2011 |
EP |
11186714.9 |
Claims
1. A control contact driving system for a plurality of power
semiconductor devices, comprising: a current driver unit configured
for providing reference currents for at least one of pulling-up and
pushing-down control contacts of the power semiconductor devices;
and a current distributor unit configured for at least one of
amplifying and distributing the reference currents to the control
contacts of the power semiconductor devices, wherein: the current
distributor unit comprises a pull-up current mirror having a
plurality of PMOS based transistors, and a push-down current mirror
having a plurality of NMOS based transistors, first main contacts
of all pull-up transistors are connected in parallel to a first
voltage source, and first main contacts of all push-down
transistors are connected in parallel to a second voltage source
having a lower voltage than the first voltage source; a second main
contact of a corresponding one of the pull-up transistors and a
second main contact of a corresponding one of the push-down
transistors are respectively connected together and configured for
providing current to a respective control contact of a
corresponding one of the power semiconductor devices, respectively;
and the control contacts of the pull-up transistors are all
connected in parallel to the current driver unit for receiving a
pull-up current, and the control contacts of the push-down
transistors are all connected in parallel to the current driver
unit for receiving a push-down current.
2. The control contact driving system according to claim 1,
wherein: the pull-up current mirror comprises a PMOS based pull-up
reference transistor, and the push-down current mirror comprises a
NMOS based push-down reference transistor; the first main contact
of the pull-up reference transistor is connected to all first main
contacts of the pull-up transistors, and the first main contact of
the push-down reference transistor is connected to all first main
contacts of the push-down transistors; the control contact of the
pull-up reference transistor is connected to the control contacts
of the pull-up transistors, and the control contact of the
push-down reference transistor is connected to the control contacts
of the push-down transistors; and the second main contact of the
pull-up reference transistor is connected to the current driver
unit for receiving the pull-up current, and the second main contact
of the push-down reference transistor is connected to the current
driver unit for receiving the push-down current.
3. The control contact driving system according to claim 1,
comprising: a current sensor configured for detecting a malfunction
of a control contact of a corresponding one of the power
semiconductor devices, wherein the current sensor is connected to
at least one of the first main contacts of the pull-up transistors
and the first main contacts of the push-down transistors.
4. The control contact driving system according to claim 1,
wherein: the pull-up current mirror comprises a plurality of PMOS
based voltage limiting devices, and the push-down current mirror
comprises a plurality of NMOS based voltage limiting devices; and
at least one voltage limiting device is connected in series with
its main contacts between the pull-up transistor or the push-down
transistor.
5. A power semiconductor module comprising: the control contact
driving system according to claim 1; and a plurality of power
semiconductor devices, wherein: the control contact of a
corresponding one of the power semiconductor devices is connected
to the second main contact of a respective pull-up transistor and
to the second main contact of a respective push-down
transistor.
6. The power semiconductor module according to claim 5, wherein:
the power semiconductor devices are arranged in groups such that
(i) the first main contacts of the power semiconductor devices of
the respective group are all connected in parallel, and (ii) the
second main contacts of the power semiconductor devices of the
respective group are all connected in parallel.
7. The power semiconductor module according to claim 6, wherein at
least the second main contacts of a first group are connected to
the first main contacts of a second group.
8. The power semiconductor module according to claim 5, wherein the
plurality of power semiconductor devices and the current
distributor unit are bonded to a laminated substrate.
9. The power semiconductor module according to claim 5, wherein at
least one of the power semiconductor device comprises an IGBT.
10. A power semiconductor array comprising a plurality of modified
power semiconductor modules which include a plurality of power
semiconductor devices, the array comprising: a current driver unit
configured for providing reference currents for at least one of
pulling-up and pushing-down control contacts of the power
semiconductor devices; a modified current distributor unit
configured for at least one of amplifying and distributing the
reference currents to the power semiconductor modules, wherein: the
modified power semiconductor modules each comprise a plurality of
power semiconductor devices and a current distributor unit
configured for at least one of amplifying and distributing the
reference currents to the power semiconductor devices; the current
distributor unit comprises a pull-up current mirror having a
plurality of PMOS based transistors, and a push-down current mirror
having a plurality of NMOS based transistors; first main contacts
of all pull-up transistors are connected in parallel to a first
voltage source, and first main contacts of all push-down
transistors are connected in parallel to a second voltage source
having a lower voltage than the first voltage source; a second main
contact of a corresponding one of the pull-up transistor and a
second main contact of a corresponding one of the push-down
transistor are connected together with a respective control contact
of a corresponding one of the power semiconductor devices,
respectively; the control contacts of the pull-up transistors are
all connected in parallel to the modified current distributor unit
for receiving a pull-up current, and the control contacts of the
push-down transistors are all connected in parallel to the modified
current distributor unit for receiving a push-down current; the
modified current distributor unit comprises a plurality of PMOS
based transistors and a plurality of NMOS based transistors; the
control contacts of the PMOS based transistors are connected
together to the current driver unit for receiving the push-down
current, and the control contacts of the NMOS based transistors are
connected together to the current driver unit for receiving the
pull-up current; and the second main contact of a corresponding one
of the PMOS based transistors is coupled to a respective modified
power semiconductor module for providing the pull-up current, and
the second main contact of the respective modified power
semiconductor module for providing the push-down current.
11. A method for operating the control contact driving system
according to claim 1, the method comprising: providing, by the
current driver unit, a positive rectangular current as a pull-up
reference current followed by a negative rectangular current as a
push-down reference current.
12. A method according to claim 11, wherein the positive
rectangular current comprises a rectangular current I.sub.1 between
t.sub.1 and t.sub.2 followed by a rectangular current I.sub.2
between t.sub.2 and t.sub.3 followed by a rectangular current
I.sub.3 between t.sub.3 and t.sub.4, where
I.sub.1.gtoreq.I.sub.3.gtoreq.I.sub.2 and
t.sub.4.gtoreq.t.sub.3.gtoreq.t.sub.2.gtoreq.t.sub.1, and wherein
the negative rectangular current comprises a rectangular current
I.sub.5 between t.sub.6 and t.sub.7 followed by a rectangular
current I.sub.6 between t.sub.7 and t.sub.8 followed by a
rectangular current I.sub.5 between t.sub.8 and t.sub.9, where
I.sub.5.gtoreq.I.sub.6 and
t.sub.9.gtoreq.t.sub.8.gtoreq.t.sub.7.gtoreq.t.sub.6.
13. A method according to claim 13, comprising: detecting a
malfunction by at least one of (i) providing a rectangular current
I.sub.4 between t.sub.4 and t.sub.5, where I.sub.2.gtoreq.I.sub.4
and t.sub.5.gtoreq.t.sub.4, and (ii) providing a rectangular
current I.sub.7 between t.sub.9 and t.sub.10, where
I.sub.7.gtoreq..sub.5 and t.sub.10.gtoreq.t.sub.9.
14. The control contact driving system according to claim 2,
comprising: a current sensor configured for detecting a malfunction
of a control contact of a corresponding one of the power
semiconductor devices, wherein the current sensor is connected to
at least one of the first main contacts of the pull-up transistors
and the first main contacts of the push-down transistors.
15. The control contact driving system according to claim 14,
wherein: the pull-up current mirror comprises a plurality of PMOS
based voltage limiting devices, and the push-down current mirror
comprises a plurality of NMOS based voltage limiting devices; and
at least one voltage limiting device is connected in series with
its main contacts between the pull-up transistor or the push-down
transistor.
16. The power semiconductor module according to claim 7, wherein
the plurality of power semiconductor devices and the current
distributor unit are bonded to a laminated substrate.
17. The power semiconductor module according to claim 7, wherein at
least one of the power semiconductor devices comprises an IGBT.
18. A method for operating the control contact driving system
according to claim 1, the method comprising: providing, by the
current driver unit, a positive rectangular current as a pull-up
reference current followed by a negative rectangular current as a
push-down reference current.
19. The method according to claim 18, wherein the positive
rectangular current comprises a rectangular current I.sub.1 between
t.sub.1 and t.sub.2 followed by a rectangular current I.sub.2
between t.sub.2 and t.sub.3 followed by a rectangular current
I.sub.3 between t.sub.3 and t.sub.4, where
I.sub.1.gtoreq.I.sub.3.gtoreq.I.sub.2 and
t.sub.4.gtoreq.t.sub.3.gtoreq.t.sub.2.gtoreq.t.sub.1, and wherein
the negative rectangular current comprises a rectangular current
I.sub.5 between t.sub.6 and t.sub.7 followed by a rectangular
current I.sub.6 between t.sub.7 and t.sub.8 followed by a
rectangular current I.sub.5 between t.sub.8 and t.sub.9, where
I.sub.5.gtoreq.I.sub.6 and
t.sub.9.gtoreq.t.sub.8.gtoreq.t.sub.7.gtoreq.t.sub.6.
20. The method according to claim 19, comprising: detecting a
malfunction by at least one of (i) providing a rectangular current
I.sub.4 between t.sub.4 and t.sub.5, where I.sub.2.gtoreq.I.sub.4
and t.sub.5.gtoreq.t.sub.4, and (ii) providing a rectangular
current I.sub.7 between t.sub.9 and t.sub.10, where
I.sub.7.gtoreq.I.sub.5 and t.sub.10.gtoreq.t.sub.9.
21. A method for operating the control contact driving system
according to claim 3, the method comprising: providing, by the
current driver unit, a positive rectangular current as a pull-up
reference current followed by a negative rectangular current as a
push-down reference current.
22. The method according to claim 21, wherein the positive
rectangular current comprises a rectangular current I.sub.1 between
t.sub.1 and t.sub.2 followed by a rectangular current I.sub.2
between t.sub.2 and t.sub.3 followed by a rectangular current
I.sub.3 between t.sub.3 and t.sub.4, where
I.sub.1.gtoreq.I.sub.3.gtoreq.I.sub.2 and
t.sub.4.gtoreq.t.sub.3.gtoreq.t.sub.2.gtoreq.t.sub.1, and wherein
the negative rectangular current comprises a rectangular current
I.sub.5 between t.sub.6 and t.sub.7 followed by a rectangular
current I.sub.6 between t.sub.7 and t.sub.8 followed by a
rectangular current I.sub.5 between t.sub.8 and t.sub.9, where
I.sub.5.gtoreq.I.sub.6 and
t.sub.9.gtoreq.t.sub.8.gtoreq.t.sub.7.gtoreq.t.sub.6.
23. A method according to claim 22, comprising: detecting a
malfunction by at least one of (i) providing a rectangular current
I.sub.4 between t.sub.4 and t.sub.5, where I.sub.2.gtoreq.I.sub.4
and t.sub.5.gtoreq.t.sub.4, and (ii) providing a rectangular
current I.sub.7 between t.sub.9 and t.sub.10, where
I.sub.7.gtoreq.I.sub.5 and t.sub.10.gtoreq.t.sub.9.
24. A method for operating the power semiconductor module according
to claim 5, the method comprising: providing, by the current driver
unit, a positive rectangular current as a pull-up reference current
followed by a negative rectangular current as a push-down reference
current.
25. The method according to claim 24, wherein the positive
rectangular current comprises a rectangular current I.sub.1 between
t.sub.1 and t.sub.2 followed by a rectangular current I.sub.2
between t.sub.2 and t.sub.3 followed by a rectangular current
I.sub.3 between t.sub.3 and t.sub.4, where
I.sub.1.gtoreq.I.sub.3.gtoreq.I.sub.2 and
t.sub.4.gtoreq.t.sub.3.gtoreq.t.sub.2.gtoreq.t.sub.1, and wherein
the negative rectangular current comprises a rectangular current
I.sub.5 between t.sub.6 and t.sub.7 followed by a rectangular
current I.sub.6 between t.sub.7 and t.sub.8 followed by a
rectangular current I.sub.5 between t.sub.8 and t.sub.9, where
I.sub.5.gtoreq.I.sub.6 and
t.sub.9.gtoreq.t.sub.8.gtoreq.t.sub.7.gtoreq.t.sub.6.
26. The method according to claim 25, comprising: detecting a
malfunction by at least one of (i) providing a rectangular current
I.sub.4 between t.sub.4 and t.sub.5, where I.sub.2.gtoreq.I.sub.4
and t.sub.5.gtoreq.t.sub.4, and (ii) providing a rectangular
current I.sub.7 between t.sub.9 and t.sub.10, where
I.sub.7.gtoreq.I.sub.5 and t.sub.10.gtoreq.t.sub.9.
27. A method for operating the power semiconductor array according
to claim 9, the method comprising: providing, by the current driver
unit, a positive rectangular current as a pull-up reference current
followed by a negative rectangular current as a push-down reference
current.
28. A method according to claim 27, wherein the positive
rectangular current comprises a rectangular current I.sub.1 between
t.sub.1 and t.sub.2 followed by a rectangular current I.sub.2
between t.sub.2 and t.sub.3 followed by a rectangular current
I.sub.3 between t.sub.3 and t.sub.4, where
I.sub.1.gtoreq.I.sub.3.gtoreq.I.sub.2 and
t.sub.4.gtoreq.t.sub.3.gtoreq.t.sub.2.gtoreq.t.sub.1, and wherein
the negative rectangular current comprises a rectangular current
I.sub.5 between t.sub.6 and t.sub.7 followed by a rectangular
current I.sub.6 between t.sub.7 and t.sub.8 followed by a
rectangular current I.sub.5 between t.sub.8 and t.sub.9, where
I.sub.5.gtoreq.I.sub.6 and
t.sub.9.gtoreq.t.sub.8.gtoreq.t.sub.7.gtoreq.t.sub.6.
29. A method according to claim 28, comprising: detecting a
malfunction by at least one of (i) providing a rectangular current
I.sub.4 between t.sub.4 and t.sub.5, where I.sub.2.gtoreq.I.sub.4
and t.sub.5.gtoreq.t.sub.4, and (ii) providing a rectangular
current I.sub.7 between t.sub.9 and t.sub.10, where
I.sub.7.gtoreq.I.sub.5 and t.sub.10.gtoreq.t.sub.9.
Description
RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C. .sctn.119
to European Patent Application No. 11186714.9 filed in Europe on
Oct. 26, 2011, the entire content of which is hereby incorporated
by reference in its entirety.
FIELD
[0002] The present disclosure relates to a control contact driving
system for a plurality of power semiconductor devices. The present
disclosure also relates to a power semiconductor module including
the control contact driving system and a plurality of power
semiconductor devices. In addition, the present disclosure relates
to a power semiconductor array including a plurality of modified
power semiconductor modules, and to a method for operating the
control contact driving system, the power semiconductor module
and/or the modified power semiconductor module.
BACKGROUND INFORMATION
[0003] Power semiconductor devices, such as insulated gate bipolar
transistors (IGBT), reverse conductive insulated gate bipolar
transistors (reverse conducting IGBT) and/or bi-mode insulated gate
transistors (BIGT), are mostly used as a fast switching device for
very high electrical currents and voltages. The popularity of IGBTs
is rising due to their excellent electrical properties and
relatively easy driving. They are widely used in applications such
as electrical motor control equipment, for example, for hybrid and
electrical cars, locomotives, ship propulsions, industrial
equipment, machineries etc., DC electrical transmission, such as
DC-AC converters, wind and solar power converters and
synchronizers, power network cosinus .phi. compensators, emergency
power supplies, etc.
[0004] Often, a plurality of IBGT dies are connected in parallel
encapsulated in a module to increase their switching capabilities,
as shown in the known configuration of FIG. 1. However, in such
parallel connection of the gates, a defect in a gate and especially
a short circuit connection between a gate and an emitter makes all
of the IGBT devices in the module uncontrollable.
SUMMARY
[0005] An exemplary embodiment of the present disclosure provides a
control contact driving system for a plurality of power
semiconductor devices. The exemplary control contact driving system
includes a current driver unit configured for providing reference
currents for at least one of pulling-up and pushing-down control
contacts of the power semiconductor devices, and a current
distributor unit configured for at least one of amplifying and
distributing the reference currents to the control contacts of the
power semiconductor devices. The current distributor unit includes
a pull-up current mirror having a plurality of PMOS based
transistors, and a push-down current mirror having a plurality of
NMOS based transistors. First main contacts of all pull-up
transistors are connected in parallel to a first voltage source,
and first main contacts of all push-down transistors are connected
in parallel to a second voltage source having a lower voltage than
the first voltage source. A second main contact of a corresponding
one of the pull-up transistors and a second main contact of a
corresponding one of the push-down transistors are respectively
connected together and configured for providing current to a
respective control contact of a corresponding one of the power
semiconductor devices, respectively. The control contacts of the
pull-up transistors are all connected in parallel to the current
driver unit for receiving a pull-up current, and the control
contacts of the push-down transistors are all connected in parallel
to the current driver unit for receiving a push-down current.
[0006] An exemplary embodiment of the present disclosure provides a
power semiconductor module which includes the above-described
control contact driving system according to the present disclosure,
and a plurality of power semiconductor devices. The control contact
of a corresponding one of the power semiconductor devices is
connected to the second main contact of a respective pull-up
transistor and to the second main contact of a respective push-down
transistor.
[0007] An exemplary embodiment of the present disclosure provides a
power semiconductor array which includes a plurality of modified
power semiconductor modules having a plurality of power
semiconductor devices. The exemplary array also includes a current
driver unit configured for providing reference currents for at
least one of pulling-up and pushing-down control contacts of the
power semiconductor devices, and a modified current distributor
unit configured for at least one of amplifying and distributing the
reference currents to the power semiconductor modules. The modified
power semiconductor modules each include a plurality of power
semiconductor devices and a current distributor unit configured for
at least one of amplifying and distributing the reference currents
to the power semiconductor devices. The current distributor unit
includes a pull-up current mirror having a plurality of PMOS based
transistors, and a push-down current mirror having a plurality of
NMOS based transistors. First main contacts of all pull-up
transistors are connected in parallel to a first voltage source,
and first main contacts of all push-down transistors are connected
in parallel to a second voltage source having a lower voltage than
the first voltage source. A second main contact of a corresponding
one of the pull-up transistor and a second main contact of a
corresponding one of the push-down transistor are connected
together with a respective control contact of a corresponding one
of the power semiconductor devices, respectively. The control
contacts of the pull-up transistors are all connected in parallel
to the modified current distributor unit for receiving a pull-up
current, and the control contacts of the push-down transistors are
all connected in parallel to the modified current distributor unit
for receiving a push-down current. The modified current distributor
unit includes a plurality of PMOS based transistors and a plurality
of NMOS based transistors. The control contacts of the PMOS based
transistors are connected together to the current driver unit for
receiving the push-down current, and the control contacts of the
NMOS based transistors are connected together to the current driver
unit for receiving the pull-up current. The second main contact of
a corresponding one of the PMOS based transistors is coupled to a
respective modified power semiconductor module for providing the
pull-up current, and the second main contact of the respective
modified power semiconductor module for providing the push-down
current.
[0008] An exemplary embodiment of the present disclosure provides a
method for operating any of the above-described control contact
driving system, power semiconductor module and/or power
semiconductor array, where the method includes providing, by the
current driver unit, a positive rectangular current as a pull-up
reference current followed by a negative rectangular current as a
push-down reference current.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Additional refinements, advantages and features of the
present disclosure are described in more detail below with
reference to exemplary embodiments illustrated in the drawings, in
which:
[0010] FIG. 1 shows a known connection of a plurality of IGBTs in
parallel;
[0011] FIG. 2 shows a known connection of the parallel IGBTs as
shown in FIG. 1 in a serial connection with IGBT drivers;
[0012] FIG. 3 shows the so-called Miller effect;
[0013] FIG. 4 shows a simplified circuit and wave forms for the
gate-emitter voltage and currents according to known
configurations;
[0014] FIG. 5 shows an individual gate driving according to a known
configuration;
[0015] FIG. 6 shows the mismatch created by technological
tolerances between drivers according to known configurations;
[0016] FIG. 7 shows three current levels during the transition
phase according to known configurations;
[0017] FIG. 8 shows a current drive mode according to an exemplary
embodiment of the present disclosure;
[0018] FIG. 9 shows a control contact driving system according to
an exemplary embodiment of the present disclosure;
[0019] FIG. 10 shows a power semiconductor module according to an
exemplary embodiment of the present disclosure;
[0020] FIG. 11 shows a possible placement of four IGBTs and two
freewheeling diodes mounted on a substrate including the control
contact driving system according to an exemplary embodiment of the
present disclosure;
[0021] FIG. 12 shows a power semiconductor array according to an
exemplary embodiment of the present disclosure;
[0022] FIG. 13 shows an example of a pull-up current and push-down
current for operating the control contact driving system according
to an exemplary embodiment of the present disclosure;
[0023] FIG. 14 shows a current sensor according to an exemplary
embodiment of the disclosure;
[0024] FIG. 15 shows an example of a current distributor unit
according to an exemplary embodiment of the present disclosure;
[0025] FIGS. 16 to 18 and 20 to 22 show simulation results achieved
with control contact driving systems according to exemplary
embodiments of the present disclosure as shown in FIGS. 15 and 19,
respectively; and
[0026] FIG. 19 shows an exemplary embodiment of an implementation
of a power semiconductor module including the control contact
driving system according to the present disclosure.
DETAILED DESCRIPTION
[0027] Exemplary embodiments of the present disclosure provide a
control contact driving system for driving the control contacts of
a plurality of power semiconductor devices, for example, IGBTs,
such that a short circuit between a control contact and a main
contact of a power semiconductor device, for example, between a
gate and an emitter of an IGBT, does not affect overall stability
and/or controllability of the whole system.
[0028] Exemplary embodiments of the present disclosure also provide
a power semiconductor module including the control contact driving
system and a plurality of power semiconductor devices, a power
semiconductor array including a plurality of modified power
semiconductor modules, and a method for operating the control
contact driving system, the power semiconductor module and/or the
modified power semiconductor module
[0029] In accordance with an exemplary embodiment, a control
contact driving system is provided for a plurality of power
semiconductor devices, where the system includes a current driver
unit configured (e.g., adapted) for providing reference currents
for pulling-up and/or pushing-down the control contacts of the
power semiconductor devices, and a current distributor unit
configured for amplifying and/or distributing the reference
currents to the control contacts of the power semiconductor
devices. The current distributor unit includes a pull-up current
mirror which includes a plurality of PMOS based transistors, and a
push-down current mirror which includes a plurality of NMOS based
transistors. The first main contacts of all pull-up transistors are
connected in parallel to a first voltage source, and the first main
contacts of all push-down transistors are connected in parallel to
a second voltage source having a lower voltage than the first
voltage source. The second main contact of a respective pull-up
transistor and the second main contact of a respective push-down
transistor are connected together and configured for providing
current to a respective control contact of a power semiconductor
device. The control contacts of the pull-up transistors are all
connected in parallel to the current driver unit for receiving a
pull-up current, and the control contacts of the push-down
transistors are all connected in parallel to the current driver
unit for receiving a push-down current.
[0030] Accordingly, the present disclosure provides current mirrors
for further amplifying and/or distributing currents for switching
the individual control contacts of a plurality of power
semiconductor devices, for example amplifying and/or distributing
positive and negative current pulses to the gates of a multi-die
IGBT module. In this such way, the control contact driving system
provides for driving more than a single control contact
respectively more than a single power semiconductor device. As the
control contacts of the individual power semiconductor devices are
driven individually, respectively, a failure of a control contact,
such as a short circuit connection between a gate and emitter of an
IGBT power semiconductor device, does not make all of the power
semiconductor devices uncontrollable. The control contact driving
system and/or the current driver unit can be implemented as a
circuit, such as a hybrid or even better integrated circuit, and
can be capsulated within the power semiconductor module, therefore
in close contact to the controlled devices, such as transistors,
for example.
[0031] The control contact driving system provides for equal
switching processes for all power semiconductor devices connected,
for example connected in parallel, by providing equal driving
currents to the control contacts of the power semiconductor
devices, thereby avoiding the mismatch from using individual
control contact drivers, as known according to conventional
techniques. In accordance with an exemplary embodiment, all
electrical devices used within the control contact driving system
are provided with "well" matched electrical properties and placed
in an equal environment in terms of temperature, supply voltage
etc., such that the respective driving currents for the control
contacts of the power semiconductor devices are also "well"
matched.
[0032] In accordance with an exemplary embodiment, the power
semiconductor devices are provided as insulated gate bipolar
transistor (IGBT), reverse conductive insulated gate bipolar
transistor (reverse conducting IGBT), bi-mode insulated gate
transistor (BIGT) and/or any other power MOSes. The control contact
can be provided as the gate, the first main contact can be provided
as the emitter, and/or the second main contact can be provided as
the collector of the power semiconductor device, for example, an
IGBT. In accordance with an exemplary embodiment, the first voltage
source provides a voltage greater than zero and/or the second
voltage source provides a voltage smaller than zero or a voltage
that is zero with respect to a main contact of the power
semiconductor device, for example, grounded to earth. In accordance
with an exemplary embodiment, the current for respectively
pulling-up the pull-up current transistors includes a current that
is greater than zero and/or the current for respectively
pushing-down the push-down transistors includes a current that is
smaller than zero. In regards to the pull-up transistors and/or the
push-down transistors, the control contact can include the gate,
the first main contact can include the source and/or the second
main contact can include the drain of the respective transistor. In
accordance with an exemplary embodiment, aforementioned transistors
are provided as field effect transistors.
[0033] In accordance with an exemplary embodiment, the pull-up
current mirror includes a PMOS based pull-up reference transistor,
and the push-down current mirror includes a NMOS based push-down
reference transistor. The first main contact of the pull-up
reference transistor is connected to all first main contacts of the
pull-up transistors, and the first main contact of the push-down
reference transistor is connected to all first main contacts of the
push-down transistors. The control contact of the pull-up reference
transistor is connected to the control contacts of the pull-up
transistors, and the control contact of the push-down reference
transistor is connected to the control contacts of the push-down
transistors. The second main contact of the push-up reference
transistor is connected to the current driver unit for receiving
the pull-up current, and the second main contact of the push-down
reference transistor is connected to the current driver unit for
receiving the push-down current. Thus, according to this
embodiment, the current, for example, current pulses coming from
the current driver unit, is applied to the reference transistor,
which can be in a "diode" connection for defining the bias voltage
for the pull-up transistors respectively push-down transistors.
[0034] In accordance with an exemplary embodiment, the control
contact driving system includes a current sensor for detecting a
malfunction of a control contact of a power semiconductor device,
whereby the current sensor is connected to the first main contacts
of the pull-up transistors and/or to the first main contacts of the
push-down transistors. This embodiment is advantageous for
detecting shorted gates, as the current sensor is configured for
measuring the value of the current flowing towards the current
distributor unit and for activating an alarm, for example, in case
the value is greater than a predefined threshold.
[0035] In accordance with an exemplary embodiment, the pull-up
current mirror includes a plurality of PMOS based voltage limiting
devices, and the push-down current mirror includes a plurality of
NMOS based voltage limiting devices. At least one voltage limiting
device is connected in series with its main contacts between the
pull-up transistor or the push-down transistor and the push-down
respectively the pull-up transistor. In accordance with an
exemplary embodiment, the voltage limiting device is provided as a
cascading transistor. Providing such voltage limiting devices as
cascading transistors, respectively, allows for limiting the
voltage across the transistor directly connected to the power
semiconductor devices and for using low voltage CMOS technology for
relatively high operating voltages.
[0036] Exemplary embodiments of the present disclosure also provide
a power semiconductor module including the control contact driving
system as described above and a plurality of power semiconductor
devices, whereby the control contact of a respective power
semiconductor device is connected to the second main contact of a
respective pull-up transistor and to the second main contact of a
respective push-down transistor.
[0037] In accordance with an exemplary embodiment, the power
semiconductor devices are arranged in groups such that the first
main contacts of the power semiconductor devices of the respective
group are all connected in parallel and such that the second main
contacts of the power semiconductor devices of the respective group
are all connected in parallel.
[0038] In accordance with an exemplary embodiment, at least the
second main contacts of a first group are connected to the first
main contacts of a second group. Arranging the power semiconductor
devices in such groups allows for switching higher voltages
respectively currents.
[0039] According to an exemplary embodiment, the plurality of power
semiconductor devices and the current distributor unit are bonded
to a laminated substrate, whereby the current distributor unit can
be implemented in CMOS or bipolar technology and mounted onto an
IGBT module substrate.
[0040] In accordance with an exemplary embodiment, the power
semiconductor device is provided as an IGBT. In another embodiment,
the current distributor unit can be arranged external to the power
semiconductor module.
[0041] Exemplary embodiments of the present disclosure also provide
a power semiconductor array including a plurality of modified power
semiconductor modules including a plurality of power semiconductor
devices, an account driver unit configured for providing reference
accounts for pulling-up and/or pushing-down control contacts of the
power semiconductor devices, and a modified current distributor
unit configured for amplifying and/or distributing the reference
currents to the power semiconductor modules. The modified power
semiconductor modules each include a plurality of power
semiconductor devices and a current distributor unit configured for
amplifying and/or distributing the reference current to the power
semiconductor devices. The current distributor unit includes a
pull-up current mirror including a plurality of PMOS based
transistors and a push-down current mirror including a plurality of
NMOS based transistors. The first main contacts of all pull-up
transistors are connected in parallel to a first voltage source,
and the first main contacts of all push-down transistors are
connected in parallel to a second voltage source having a lower
voltage than the first voltage source. The second main contact of a
respective pull-up transistor and the second main contact of a
respective push-down transistor are connected together with the
respective control contact of a power semiconductor device. The
control contacts of the pull-up transistors are all connected in
parallel to the modified current distributor unit for receiving a
pull-up current, and the control contacts of the push-down
transistors are all connected in parallel to the modified current
distributor unit for receiving a push-down current. The modified
current distributor unit includes a plurality of PMOS based
transistors and a plurality of NMOS based transistors. The control
contacts of the PMOS based transistors are connected together to
the current driver unit for receiving the push-down current, and
the control contacts of the NMOS based transistors are connected
together to the current driver unit for receiving the pull-up
current. The second main contact of a respective PMOS based
transistor is coupled to a respective modified power semiconductor
module for providing the pull-up current, and the second main
contact of the respective modified power semiconductor module for
providing the push-down current.
[0042] Further embodiments and advantages of the power
semiconductor array are derivable by one skilled in the art from
the above-described control contact driving system and/or power
semiconductor module.
[0043] Exemplary embodiments of the present disclosure also provide
a method for operating the aforementioned control contact driving
system, the power semiconductor module and/or the power
semiconductor array, whereby the current driver unit alternatively
provides a positive rectangular current as pull-up reference
current followed by a negative rectangular current as push-down
reference current. Providing such currents allow for "switching on"
respectively "switching off" the control contact of the respective
power semiconductor device.
[0044] According to an exemplary embodiment, the positive
rectangular current includes a rectangular current I.sub.1 between
t.sub.1 and t.sub.2 followed by a rectangular current I.sub.2
between t.sub.2 and t.sub.3 followed by a rectangular current
I.sub.3 between t.sub.3 and t.sub.4, whereby
I.sub.1.gtoreq.I.sub.3.gtoreq.I.sub.2 and
t.sub.4.gtoreq.t.sub.3.gtoreq.t.sub.2.gtoreq.t.sub.1. The negative
rectangular current includes a rectangular current I.sub.5 between
t.sub.6 and t.sub.7 followed by a rectangular current I.sub.6
between t.sub.7 and t.sub.8 followed by a rectangular current
I.sub.5 between t.sub.s and t.sub.9, whereby I.sub.5.gtoreq.I.sub.6
and t.sub.9.gtoreq.t.sub.8.gtoreq.t.sub.7.gtoreq.t.sub.6. Using
such a rectangular current that succeeds behind each other improves
the switching algorithm for switching on respectively off the
control contacts of the power semiconductor devices.
[0045] In accordance with an exemplary embodiment, the step of
detecting a malfunction comprises providing a rectangular current
I.sub.4 between t.sub.4 and t.sub.5, whereby I.sub.2.gtoreq.I.sub.4
and t.sub.5.gtoreq.t.sub.4, and/or by providing a rectangular
current I.sub.7 between t.sub.9 and t.sub.10, whereby
I.sub.7.gtoreq.I.sub.5 and t.sub.10.gtoreq.t.sub.9. Thus, after
before-described "transition phase" between t.sub.1 and t.sub.4 a
"detection phase" follows between t.sub.4 and t.sub.5 with a lower
value I.sub.4 for power saving, whereby I.sub.4 can flow through
the reference transistor and the voltage source. The same applies
for t.sub.9 and t.sub.10.
[0046] A drawback known from conventional techniques, when using
parallel connections of IGBTs capsulated in a module for increasing
the switching capabilities, as shown in FIG. 1, is that a gate
defect and especially a short circuit connection between a gate and
an emitter makes all of the IGBT devices in the module
uncontrollable. For improving of a blocking voltage capability,
more modules may be connected in a serial connection as shown in
FIG. 2. In case of a defect in an IGBT, the overall system should
continue to operate using the remaining IGBT devices with a
slightly reduced current capability or to close all IGBT devices
from corresponding rows and to continue to operate with
respectively a slightly reduced blocking voltage capability.
However, the parallel connection of the gates of the IGBTs makes
such features impossible: A short circuit connection in one gate
causes a voltage block for all other gates in the corresponding
row. Different solutions for solving the aforementioned problem
have been proposed according to known configurations.
[0047] Within a first solution, a shorted gate can be detected by
the existence of gate current outside of the transition phase
between switching on and off respectively off and on an IGBT
device. However, the exact number of defected gates cannot be
detected with such group driving. In some cases, the number of
defected gates is important information that has to be known.
[0048] Another problem is the capacitive coupling between the
collector and gate, the so-called Miller effect, as shown in FIG.
3. The capacitive coupling causes a voltage drop in the rising and
falling signal edge, and delays the commutation as shown in FIG.
3.
[0049] The known voltage mode control with the gate resistor
limiting the switching speed has a reduced immunity against the
capacitive collector gate coupling due to the exponential
decreasing of the current during the transition phase. The gates of
the IGBTs behave as capacitors, while two resistors may be used for
charging and discharging of the gates. Eventually one resistor may
be used for both processes, as shown in FIG. 4, which illustrates a
simplified circuit and wave forms of the gate emitter voltage and
current.
[0050] The gate voltage and current follows the equation
V(t)=V.sub.o*(1-e.sup.-(t/RC)), I(t)=I.sub.o*e.sup.-(t/RC). As can
be seen from FIG. 4, and also shown by the equation, the gate
voltage rises, while the gate current reduces exponentially and
after a certain value the gate may become sensitive for currents
pushed through the reverse collector gate coupling.
[0051] This problem has been addressed by an individual gate
driving as shown in FIG. 5, whereby each gate has a dedicated gate
driver. In case of failure in one gate, the remaining IGBT devices
will continue to operate correctly. However, a problem in this
configuration is the mismatch between the gate drivers: a gate
driver usually includes a complex application specific integrated
circuit (ASIC) contenting a big amount of components. Therefore,
the technological tolerances often cause a big mismatch between the
drivers as shown in FIG. 6.
[0052] Such mismatch causes different delays between the inputs and
the outputs of the drivers, which means that some IGBTs may open
earlier than others, taking the whole load for a certain moment.
This weakness reduces the reliability of the overall system due to
the permanent overloading of these devices. A further problem is an
increased price due to the big amount of gate drivers and
corresponding connections required.
[0053] In another known solution, the applying of current mode
reduces the negative influence of the aforementioned Miller effect.
However, the problem with the mismatch between the drivers also
remains with this solution. Another approach is the use of variable
currents for realizing improved switching, for example, three
current levels during the transition phase between t.sub.1 and
t.sub.4, as shown in FIG. 7, for switching an IGBT between an
off-state in t.sub.1 to an on-state in t.sub.4.
[0054] During an initial moment between t.sub.1 and t.sub.2, the
gate driver pushes a higher current I.sub.1 to the gate for faster
achieving the gate threshold voltage V.sub.TH. After this value,
the IGBT starts to conduct and a current can be reduced to the
value I.sub.2 to limit the switching speed and respectively to
protect the system from over-voltage in case of inductive load.
When the gate voltage achieves a value V.sub.3, where the reverse
coupling increases its influence, for example, the capacitive
sinking of current from the gate, then the gate current can be
increased to the value I.sub.3 to compensate the current lost
during the final moment.
[0055] Exemplary embodiments of the present disclosure provide a
current driver unit 1 that, instead of voltage, uses a constant
current for controlling the gate of an IGBT, whereby the currents
are applied in difference directions depending from the operation,
for example, for turning on or turning off the IGBT. FIG. 8 shows
an exemplary embodiment for the currents provided by the current
driver unit 1.
[0056] As can be seen, rectangular current pulses are used, a
positive current pulse and a negative current pulse. These two
current sources provide accurate currents for pulling-up and
pushing-down the gate. Using such current driver unit 1, the gate
voltage rises linearly with a constant speed. In other words, the
currents applied to the gate causes the gate capacitance linearly
raising or respectively falling voltages. The respectively rising
falling voltage speed depends from the gate capacitance and the
value of the pull-up and push-down currents and can be controlled
by changing these currents. The charging and discharging currents
have a constant value in an ideal case and exist during the
transient phase only. When the gate voltage achieves the value
close to the supply voltage, then the current stops the flow. The
applying of constant currents thereby reduces the Miller effect,
for example, the effect of coupling between the collector and the
gate. Thereby, it is thoroughly possible to have more current
sources and switches to provide a current shape as discussed in
more detail below with reference to FIG. 13.
[0057] Exemplary embodiments of the present disclosure provide for
the use of two current mirrors 2 making up a current distributor
unit 3 to further amplify and/or distribute the current pulses of
the gates of a multi-die IGBT module. In this manner, the control
contact driving system can drive a plurality of gate IGBT devices,
respectively. The current mirrors 2 can be implemented as a
circuit, for example, as a hybrid or integrated circuit, and can be
encapsulated in the IGBT module. For example, the current mirrors 2
can be provided close to the controlled IGBTs. FIG. 9 shows an
exemplary embodiment of the present disclosure as described
before.
[0058] The current pulses coming from the external IGBT driver, the
current driver unit 1, are applied to NMOS based respectively PMOS
based reference transistors MN1 and MP1. The reference transistors
are in a "diode" connection, for example, and they define the bias
voltage for the transistors MN2, MN3 etc. and MP2, MP3 etc.
[0059] Connecting the gate to the drain sets the operation point in
the saturation area, because the drain-source voltage V.sub.DS in
this case is always above or equal to the saturation voltage
V.sub.DSsat=V.sub.GS-V.sub.TH. The transistors behave as current
sources and their drain current can be figured out with the
equation:
I.sub.D=(1/2)*.mu..sub.n*C.sub.ox*(W/L)*(V.sub.GS-V.sub.TH).sup.2*(1+.lam-
da.*(Vos-V.sub.DSsat), where .mu..sub.n is the charge-carrier
effective mobility, C.sub.ox is the gate oxide capacitance per unit
area, W is the gate width, L is the gate length, .lamda. is
channel-length modulation parameter and
V.sub.DSsat=V.sub.GS-V.sub.TH.
[0060] A current flowing through the drain of MN1/MP1 causes a
V.sub.GS satisfying the relation above. Because the same V.sub.GS
is applied to the other transistors, their drain currents depend
from their W/L in respect to the W/L of the reference transistor,
satisfying the relation below, given for the first 2 transistors
MN2 and MP2:
I.sub.DMN2/I.sub.DMN1=(W.sub.MN2/L.sub.MN2)/(W.sub.MN1/L.sub.MN1)or
respectively
I.sub.DMP2/I.sub.DMP1=(W.sub.MP2/L.sub.MP2)/(W.sub.MP1/L.sub.MP1).
[0061] Because of channel-length modulation, the current mirror 2
has a finite output resistance given by the r.sub.o of the output
transistor: r.sub.o=1/(.lamda.*I.sub.D). The output resistance and
the current accuracy can be respectively improved by utilizing
cascading techniques.
[0062] The current mirrors 2 can also amplify the input currents.
As shown above, the amplification factor depends from the W/L ratio
between the mirroring and the referencing transistors. In this
case, the external current driver unit 1 can have a low power
outputs, respectively, and the power amplification can be performed
in the current distributor unit 3. In accordance with an exemplary
embodiment, the current mirrors 2 can utilize a uniform structure,
for example, MOS finger, repeated many times for a better matching
and respective accuracy. This approach thus defines an integer
amplification factor. The complete driving circuit 1, 3 will
include two components, for example, the current driver unit 1 and
a power semiconductor module 4 including the current distributor
unit 3, as shown in FIG. 10.
[0063] One possible placement in case of 4 IGBTs and 2 freewheeling
diodes mounted on a common substrate is shown in FIG. 11.
[0064] The current driver unit 1 might be integrated in an ASIC,
while in an alternative embodiment the current driver unit might
also be placed externally. The current distributor unit 3 is placed
between the IGBTs. The gates G1 . . . G4 are bonded to the ASIC.
The ASIC is bonded to the laminated substrate and connected with
metal tracks to the terminals. Four terminals are provided, for
example, two inputs for pull-up and push-down currents, and two
supplies. The emitters E1 . . . E4 and anodes A1, A2 may be bonded
to the substrate and connected to the power terminals or
alternatively contacted, pressed or soldered, and connected from
the upper side.
[0065] Another opportunity is the multilevel current distribution.
For example, a modified current distributor unit 5 may drive other
current distributors units 3, integrated in the IGBT modules. A
possible configuration is presented in FIG. 12 realizing such a
power semiconductor array. This hierarchical implementation allows
the driving of large IGBT arrays using a single driver.
[0066] To detect shorted gates, a current sensor 6 can be
introduced in the power supply of the current distributor unit 3.
The current sensor 6 measures the value of the current flowing
towards the current distributor unit 3 and converts it in most of
the cases to a proportional voltage. One or more comparators can
compare the measured value to a reference value. Outside the
transition phase, only the input current flows through the supply.
An exemplary waveform for the operating the control contact driving
system, for example, the pull-up and push-down currents, is shown
in FIG. 13.
[0067] The transition phase implements the algorithm presented in
FIG. 7. Alternatively, the shape of the current pulse may be
different depending from the used switching algorithm. In the
simplest case, the shape may be rectangular for a single current
source. After the transition phase, the current applied to the
current distributor unit 3 may be reduced to a lower value I.sub.4
for power saving. The current I.sub.4 flows through the reference
transistor and the power supply. After the transition phase the
gates are expected to be completely charged and they shouldn't
consume current. In case of shorted gate or gates, the supply
current is the sum of the current I.sub.4 and the short circuit
current or currents. The total supply current is:
I.sub.PS=I.sub.4+N*(I.sub.4*A) where N is the number of the broken
gates and A is the amplification factor of the current distributor
unit 3. Several comparators can compare the measured value with
properly selected reference values and in such way to detect the
number of the broken gates. An example is presented in FIG. 14.
[0068] The strobe pulse has to be applied within the detection
phase. The data are in the so called "thermometric code". The
current sensor may have different implementations, for example:
resistor with differential amplifier, current transformer, hall
sensor etc.
[0069] The functionality of the current distributor was proved by
simulations using 2 um CMOS technology. A small reference circuit
implementing the standard method was used for a comparison.
[0070] A further implementation of the current distributor is
presented in FIG. 15. The schematic includes the external IGBT
driver 1 presented with current pulse sources I.sub.1 and I.sub.2.
I.sub.2 acts as pull-up output and I.sub.1 respectively as
push-down output. The current distributor unit 3 contents the PMOS
current mirrors 2 implemented with MP10 to MP14 and NMOS current
mirrors 2 implemented with MN10 to MN14. The PMOS current mirrors 2
perform the pull-up operation and the NMOS current mirrors 2 the
push-down operation.
[0071] The simulation results using the control contact driving
system are presented in FIGS. 16 to 18. The dotted line presents
the known method. The solid line presents the method according to
the present disclosure. In sum, the simulated result demonstrates
an improved switching process with the method according to the
present disclosure.
[0072] A more advanced circuit utilizing wide swing current mirrors
2 with improved characteristics and cascading transistors allowing
limiting of the voltage across the output transistors and
respectively using of low voltage CMOS technology for relatively
high operating voltages is presented in FIG. 19. The results by
using this embodiment are given in FIGS. 20 to 22 below. The
waveforms of the known method are presented as dotted lines. The
solid line waveforms present the method according to the present
disclosure.
[0073] The embodiment from FIG. 19 demonstrates improved
characteristics and especially more accurate current pulses,
compared to the embodiment from FIG. 15. Another advantage is that
the voltage during the OFF state is distributed over 3 MOS
transistors and it allows the using of low voltage CMOS technology.
The low voltage MOS transistors have better matching between the
devices due to the used self-centred gate technology.
[0074] Other variations to the disclosed embodiments can be
understood and effected by those skilled in the art in practicing
the claimed disclosure, from a study of the drawings, the
disclosure, and the appended claims. In the claims, the word
"comprising" or "including" does not exclude other elements or
steps, and the indefinite article "a" or "an" does not exclude a
plurality. The mere fact that certain measures are recited in
mutually different dependent claims does not indicate that a
combination of these measures cannot be used to advantage. Any
reference signs in the claims should not be construed as limiting
the scope.
[0075] It will be appreciated by those skilled in the art that the
present invention can be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
presently disclosed embodiments are therefore considered in all
respects to be illustrative and not restricted. The scope of the
invention is indicated by the appended claims rather than the
foregoing description and all changes that come within the meaning
and range and equivalence thereof are intended to be embraced
therein.
REFERENCE SIGNS LIST
[0076] 1 Current driver unit [0077] 2 Current mirror [0078] 3
Current distributor unit [0079] 4 Power semiconductor module [0080]
5 Modified current distributor unit [0081] 6 Current sensor
* * * * *